Who will challenge Federer 8 times this year?

I found it interesting that in the last 2 seasons, Federer has played a player 8 times during the course of the season.
2011 it was Tsonga, 6-2 in Fed's favor, then 2012 it was Del Potro, again 6-2 in Fed's favor.

So who will be the player this year to challenge Fed 8 times or more?
What will the H-H look like?

So far, Davydenko is the only player to have played Fed twice this season (lost both times)
Will he run into Fed 6 more times this year?
Will he lose them all?

If Fed plays Berdych 8 times this year, i think Berdych will win more than he loses, something like 5-3. Fed will have an advantage i believe at Indian Wells, Madrid, Halle but that's only if he can close out the match :neutral: